Fuse clamp



1943- E. w. LANDMEIER 2,448,267

FUSE CLAMP Filed June 22, 1945 v IN V EN TOR.

the current to the jaws.

Patented Aug. 31, 1948 V UNITED STATES PATENT OFFICE Fuss CLAMP Edwin WrLand meier, Lakeside Park, Ky. ApplicationJune 22, 1945, Serial No. 01,004 8 Claims. (01. 1 34 8) This invention relates to fuse clamps which are adapted to receive the endwise portions of a cartridge fuse.

The principal purpose of this invention has been to provide an improved fuse clamp which is capable of forming a rigid and secure connect-ionwith the fuse terminal through a. minimum oflmechanical joints carrying electricity. Conventional fuse clamps consist of yieldable jaws mounted upon a block of insulating material and arranged for the reception between the jaws of the terminal portion of the fuse, while various types of connectors are employed for carrying Sometimes the jaws are provided with screws or clamps for drawing them together against the fuse terminal. However, structures of this general type, during service over continued periods, tend to become heated not only because of poor contact between the jaws and the fuse terminal, but also between the various mechanically associated'connectors or parts intervening between the fuse terminal andthe electric wire or bus bar which carries the current to the fuse. Briefly, the present invention contemplates a structure in which mechanical joints which carry current are reduced to a minimum by support ing the fuse terminals directly on bus bars or equivalent conductors, and by the utilization of one or more jaws which press upon the fuse terminal to establish good and secure contact thereof with the conductor. Otherwise expressed, the invention comprehends a structure inwhich the jaws are not serially connected in the circuit, as

heretofore, but rather are only supplemental mechanical devices not actually forming a part of the electrical circuit but effective 'for exerting adequate pressure to insure contactbetween the electrical parts. By virtue of this construction, the jaws may be constructed without regard to their electrical conductive properties and thereforemay be made of materials more rigid and less subject to fatigue or failure through heating than fuse jaws which have been used in the past.

In the preferred embodiments of the improvement the terminal of the fuse is seated directly upon an electrical conductor. The jaw or clamp portion of the assembly is mechanically sustained upon a suitable base and it extends around the conductor to embrace the fuse terminal and hold it in its seated position against the conductor. In this structure therefore the only electrical connection atwhich heating through. poor surface contact can occur is. that contact between the se and t conductor. and. he p ssibility of failure at such point is reduced because the clamp may be made of strong materials chosen for their mechanical reliability without regard to their electrical conductivity.

Other features of the invention are disclosed in the following description of the drawings in which a -preferred embodiment of the improvement is illustrated and, from the foregoing description of thegeneral principles upon which the invention is predicated, as well as the following detailed description, those skilled in the art will comprehendthe various modifications to which the invention is susceptible.

' In the drawings: l

f Figure 1 is aplan view of a fuse block equipped with clamps constructed in accordance with the present invention.

Figure 2 is a side view of the fuse block assembly.

, Figure 3 is a. cross sectional elevation taken on the line 3'-'3 of Figure 2. v

. Figure 4 is a fragmentary view similar to Figure 2 showing a modified form of fuse clamp. Figure '5 is a'view taken on the line 5-5 of Figure 4.

Figure 6 is a view similar to Figure 2 of another modified form of fuse clamp.

QFlgure '7 is a sectional view taken on the line 'I'-'| of Figure 6.

The fuse block assembly, as shown in Figure 1, comprises the conventional base I of suitable insulating material which may be adapted for panelboard or fuse box mounting in the conventional manner. The base is drilled and counterbored as at 2-2 for the reception of screws 3, the heads of which are located in the counterbores and. are spaced inwardly from the back face of the mounting block. These screws extend upwardly through brackets 4-4, which are configurated to provide seats 5, for conductor pieces B- -G, having screws 1 or other suitable connectors at their outer ends to which electric wires or bus bars may be attached.

The screws 3 are threaded into the conductors 8 and serve as clamps for binding the conductors against the seats of the brackets 4 and, in turn, binding the brackets 4 firmly against the mounting block. However, clamp elements 8 also are utilized; these pieces have base portions thereof located between the conductors 6 and the brackets l, and the clamps 8 therefor also are mounted rigidly upon the base along with the other elements. It is to be noted that the clamps do not form any part of the electrical circuit for conveying current from the conductors 6 to the fuse.

Instead current passes directly from the conductor 6 to the fuse without regard to the clamps. The clamps therefore function only in a mechanical way.

Different types of structures are shown in the drawings to illustrate the different manners in which fuses may be accommodated. In the structure shown in Figures 1 to 3 the fuses have bladetype terminals and these are mounted vertically, i. e. laterally with respect to the base I; in Figures 4 and 5 blade-type fuses are mounted with the blades seated flatwise or horizontally, rather than edgewise on the conductor 6; and in Fig,- ures 6 and 7 fuses having ferrule terminals are accommodated. r

For edgewise reception of blade-type fuse terminals the brackets 4 have upwardly extending portions 9 which clusters 6 and extend upwardly above the upper surfaces of the conductors. The projectingv portions of the brackets are notched, as at I0, whereby recesses or guide slots are formed, substantially as wide as the fuse blade, to receive an edgewise portion of each blade and support the blade until it is firmly clamped in place. The fuse blade is indicated at I l and the notch construction is shown best in Figure 3. It is to be noted that one of the walls delineating the notch extends above the other forming an abutment to hold the blade in a substantially vertical position, While the portion of the bracket at the other side of the blade is cut away on an angle which forms a clearance-way to facilitate easy insertion of the fuse blade into the notch. The bottom of ductor 6 toform a line contact therewith.

In this structure clamp member 8 extends laterally from the lower part thereof which is caught between the conductor 6 and the bracket, and is configurated in the form of a neck I 2 from which the clamp extends upwardly on an angle terminating in another neck I 3 having a tab portion l4 extending outwardly and upwardly therefrom. The upper neck l3 embraces the upper longitudinal edge of the fuse blade. This clamp is constructed of yieldable material, spring steel, for instance, or Phosphor bronze, or other material which may be selected particularly because of its springiness and strength and without regard for its electrical conductivity. The tab [4' provides the means for releasing the fuse from the clamp; when bent backwardly the upper neck of tab I4 is sprung away from the upper edge of the fuse and the fuse may be removed easily.

In the structures shown in Figures 4 and 5 the blade II of the fuse rests fl-atwise upon the conductor 6, in facial engagement therewith, Whereby a substantial area of contact is established between the .two. In this modified form the clamp element, l5, has one portion extending laterally from between the conductor and the seat of bracket 4, upwardly around the edge of the fuse blade, and over the fuse blade where it terminates at a pressure portion l6 which is located so as to engage substantially the .central portion of the blade and press it toward the conductor. At the opposite side, the clamp member has an upwardly extending portion I1 configurated approximately to the contour of an edge of the fuse blade to form a guide or locator which assists in the positioning of the blade on the conductor.

lie along the ends of the contudinal movement a lip 20 may extend above the upper surface of each conductor 6 adjacent the endwise portion of the fuse terminal, to serve as an abutment therefor.

Having described my invention, I claim:

1. A fuse clamp comprising a base, a conductor fastened on said base, a yieldable clamp, said yield-able clamp having a portion interposed between said base and said conductor so as to be mechanically fastened in place by said conductor and having another portion extending upwardly above said conductor for yieldable pressure engagement with one portion of a fuse terminal which has an opposite portion thereof seated on said conductor.

2. A fuse clamp comprising a conductor, .a base, a clamp held between said base and said conductor and having a portion extending above said conductor for pressure engagement with one portion of a fuse terminal while an opposite portion thereof is in engagement with said conductor.

3. A fuse clamp comprising a conductor, a base, a clamp held between said base and said conductor and having a portion extending above said conductor for pressure engagement with one portion of a fuse terminal while an opposite portion thereof is in engagement with said conductor, and means presenting :a guide notch within which said fuse terminal is located and sustained subject to the pressure of said clamp.

4. A fuse clamp comprising a base, a conductor, a clamp having a portion caught between said conductor and said base, a portion of said clamp extending above said conductor for engagement with an upper edgewise portion of a fuse blade While a lower opposite edgewise portion of the fuse blade in in engagement with said conductor, and means presenting a notch for sustaining the blade in a position substantially perpendicular to said :conductor subject to the pressure of said clamp.

5. A fuse clamp comprising a base, a conductor, a clamp having a portion caught between said conductor and said base, a portion of said clamp extending above said conductor for engagement with an upper edgewiseportion of a fuse blade While a lower opposite .edgewise portion of the fuse blade is in engagement with said conductor, and means presenting .an inclined surface extending later-ally of said fuse and terminating in a slot positioned to receive the fuse blade and sustain it in a position substantially perpendicular to said conductor under the pressure of said clamp.

6. A fuse clamp comprising a base, a conductor, and a clamp interposed between said base and said conductor, one portion of said clamp extending upwardly at one side of said conductor and 'over said conductor for pressure engagement with one face of a fuse blade having its opposite face resting on said conductor, said clamp having another portion which extends upwardly at the opposite side of said conductor and forms a locating guide for a longitudinal edge oat said blade.

'7. A fuse clamp comprising a conductor, a yieldable member having a portion extending upwardly above said conductor along one side thereof, the upper portion oi said yieldable member overhanging said conductor and being configurated in the form of a claw for engaging the upper surface of a fuse terminal, the opposite surface of which is seated upon said conductor, and a tab portion extending from said claw.

8. A fuse clamp comprising a bracket presenting a seat portion, a conductor seated on said bracket, a yieldable member having a lower 6 end supported against movement, an arcuately shaped portion extending from said supported end, an arm extending upwardly above said conductor from said arcuately shaped portion and terminating in a claw portion overhanging said 'c-onductor for engaging the upper surface of a fuse terminal, the opposite end of which is seated upon said conductor.

EDWIN W. LANDMEIER.

REFERENCES CITED The following references are of record in file of this patent:

UNI'IED STATES PATENTS the 

